The market order and the limit order are known as transaction methods for the financial product, for example, the foreign exchange. The market order means the order form in which the dealer performs the transaction by the price at the time the customer executes an order. The limit order means the order form in which the customer designates the trade price in advance and the dealer performs the transaction when the market price is equal to the designated trade price. In other words, the dealer who receives the limit order buys the corresponding financial product when the price of it falls to the designated price or sells the corresponding financial product when the price of it rises to the designated price. The invention for performing the limit orders of the financial products using a computer is previously known (described in the patent document 1, for example).